苄基锡烯或炔基膦酸酯的合成

合成了具有通式为（ＰｈＣＨ２Ｓｎ）ｎ－１Ｏ２Ｐ（Ｏ）Ｒ（ｎ＝２，３；Ｒ＝－Ｃ＝ＣＰｈ，－Ｃ＝ＣＣ５ｈ１１－ｎ，－Ｃ＝ＣＣＨ２ＯＣＨ３，－ＣＨ＝ＣＣＩＰＨ）的８个苄基锡烯或炔基膦酸酯，并通过元素分析、ＩＲ和１ＨＮＭＲ对其进行了表征。     

系列同三核铬、锰、铁羧酸配合物的FAB-MS研究

进行了系列同三核羧酸配合物〔Ｍ３Ｏ（Ｏ２ＣＲ）６Ｐｙ３〕Ｘ（Ｍ＝Ｃｒ,Ｍｎ,Ｆｅ;Ｒ＝ＣＨ３,Ｃ２Ｈ５,Ｃ６Ｈ５;Ｘ＝Ｃｌ－,ＣｌＯ４－;Ｐｙ为吡啶）的快原子轰击质谱（ＦＡＢ－ＭＳ）研究。获得了包括配位吡啶在内的完整阳离子峰。在研究其断裂规律时,主要观察到４个系列碎片离子：Ⅰ．〔Ｍ３Ｏ（Ｏ２ＣＲ）ｎ〕＋,ｎ＝６～２;Ⅱ．〔Ｍ３Ｏ（Ｏ２ＣＲ）ｎＯ〕＋,ｎ＝５～１;Ⅲ．〔Ｍ２Ｏ（Ｏ２ＣＲ）ｎ〕＋,ｎ＝３～１;Ⅳ．〔Ｍ２（Ｏ２ＣＲ）ｎ〕＋,ｎ＝４～２。通过对该系列配合物质谱断裂过程的比较和分析,获得了配合物稳定性随金属离子及配体的变化如下：金属离子,Ｃｒ＞Ｍｎ＞Ｆｅ;桥配基,－ＣＨ３ＣＯ２＞－Ｃ２Ｈ５ＣＯ２＞－Ｃ６Ｈ５ＣＯ２;端配基,Ｐｙ＞Ｈ２Ｏ。本研究及先前的工作〔１,８〕还为某些三核铬,铁羧酸配合物在以乙炔加水或加氢为探针反应中存在活性物种：〔Ｃｒ３Ｏ（Ｏ２ＣＲ）３～４〕,〔Ｆｅ３Ｏ（Ｏ２ＣＲ）３〕和〔Ｆｅ３Ｏ－（Ｏ２ＣＲ）Ｏ〕～〔Ｆｅ３Ｏ４〕提供了佐证     

金属键有机化合物的研究──非对称型η~5－取代环戊二烯基三羰基钼（钨）金属单键化合物的合成及表征

通过η５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭＮａ与η~５－Ｒ~２Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭＮａ（Ｍ＝Ｍｏ，Ｗ）以及η~５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭｏＮａ与η~５－Ｒ~２Ｃ＿５Ｈ＿４（ＣＯ）＿３ＷＮａ在Ｆｅ＿２（ＳＯ＿４）＿３醋酸水溶液作用下的交叉氧化偶联反应，合成了７个新的非对称型金属单键化合物η~５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）－３Ｍｏ─Ｍｏ（ＣＯ）＿３Ｃ＿５Ｈ＿４Ｒ~２－η~５（Ｒ~１，Ｒ~２：Ｃ（Ｏ）Ｍｅ，ＣＯ２Ｅｔ），η５－Ｒ１Ｃ５Ｎ４（ＣＯ）３Ｗ─Ｗ（ＣＯ）３Ｃ５Ｈ４Ｒ２－η５（Ｒ１，Ｒ２：Ｃ（Ｏ）Ｍｅ，ＣＯ２Ｅｔ；Ｈ，ＣＯ２Ｅｔ）和η５－Ｒ１Ｃ５Ｈ４（ＣＯ）３Ｍｏ─Ｗ（ＣＯ）３Ｃ５Ｈ４Ｒ２－η５（Ｒ１，Ｒ２：Ｃ（Ｏ）Ｍｅ，Ｈ；Ｅｔ，Ｃ（Ｏ）Ｍｅ；Ｃ（Ｏ）Ｍｅ，ｎ－Ｂｕ；ＣＯ２Ｍｅ，ｎ－Ｂｕ）．用Ｃ／Ｎ分析、ＩＲ、１ＨＮＭＲ和ＭＳ表征了它们的结构，并对该氧化偶联反应的特点进行了讨论．     

新型含钌异核过渡金属簇合物的合成及其结构表征

利用金属交换法合成了四个新的含钌手性过渡金属簇合物［ＭＲｕＣｏ（ＣＯ）_８（μ_３－Ｓｅ）［η_５－Ｃ_５Ｈ_４Ｃ（Ｏ）Ｒ｝］（ １ Ｍ＝ Ｍｏ, Ｒ＝ ＯＥｔ; ２ Ｍ＝ Ｗ, Ｒ＝ ＯＥｔ; ３ Ｍ＝ Ｍｏ, Ｒ＝ ＣＨ_２ＣＨ_２ＣＯＯＭｅ; ４ Ｍ＝ Ｗ, Ｒ＝ ＣＨ_２ＣＨ_２ＣＯＯＭｅ）,并用红外、核磁、元素分析测试结果进行表征,对簇合物１进行了单晶结构测定,晶体属单斜晶系,Ｐ２_１／ｎ空间群,晶胞参数ａ＝１０．１６８（２）Ａ,ｂ＝９．０１８（２）Ａ,ｃ＝２３．１２１（３）Ａ,β＝９２．５０（１）°,Ｚ＝４。     

二［氧合—二（4—二茂铁基苯甲酸二烷基锡（Ⅳ））］配合物？…

合成了｛［（ｎ－Ｂｕ）２Ｓｎ（４－Ｆｃ－Ｃ６Ｈ４ＣＯＯ）］２Ｏ｝２（１）和｛［ｎ－Ｏｃｔ）２Ｓｎ（４－Ｆｃ－Ｃ６Ｈ４ＣＯＯ）］２Ｏ｝２（２）（Ｆｃ＝ｆｅｒｒｏｅｎｙｌ两组新的配合物,对其进行了元素分析,并用ＩＲ,ＮＭＲ（＾１Ｈ,＾１３Ｃ,＾１１９Ｓｎ）进行了谱学表征,单晶Ｘ射线衍射法测定表明,配合物１的晶体属单斜晶系,Ｐ２１／ｃ空间群,晶胞参数ａ＝１．２９８８（１）ｎｍ,ｂ＝２．６５５（１）ｎｍ,     

二丁基锡氮杂环羧酸酯的合成

合成了１０种二丁基锡氮杂环羧酸酯（ｎ－Ｃ４Ｈ９）２Ｓｎ（Ｃｌ）２－ｎ（Ｏ２ＣＲ）ｎ（ｎ＝１,２;Ｒ＝吡啶基,吲哚烷基）,利用元素分析,ＩＲ及＾Ｈ ＮＭＲ表征了它们的结构。     

含硅二硫代磷酸酯的合成及生物活性

硅基甲硫醇Ｒ＾１Ｒ＾２ＣＨ３ＳｉＣＨ２ＳＨ与Ｏ，Ｏ－二烷基二硫代磷酸酯（ＲＯ）２Ｐ（Ｓ）ＳＨ及甲醛可顺利地发生类Ｍａｎｎｉｃｈ缩合反应，利用此反应和硅基甲硫醇与Ｏ，Ｏ－二乙基－Ｓ（２－溴乙基）二硫代磷酸酯的取代反应合成了３７种新的含硅二硫代到酯化合物（ＲＯ）２Ｐ（Ｓ）Ｓ（ＣＨ２）ｎＳＣＨ２ＳｉＣＨ３Ｒ＾１Ｒ＾２（ｎ＝１，２），在初筛浓度下，该类化合物具有一定的杀虫，杀螨活性。     

二苯基锡不饱和烃基膦酸酯的合成及其结构表征

以二苯基二氯化锡和炔（烯）基膦酸盐为原料,在乙醇中反应,合成了８种新的二苯基锡不饱和烃基膦酸酯Ｐｈ２ＳｎＯ２Ｐ（Ｏ）Ｒ（Ｒ＝Ｃ－－－ＣＣ３Ｈ７－ｎ,Ｃ－－－ＣＣ４Ｈ９－ｎ,Ｃ－－－ＣＣ５Ｈ１１－ｎ,Ｃ－－－ＣＣ５Ｈ１３－ｎ,Ｃ－－－ＣＣＨ２ＯＣＨ３,Ｃ－－－ＣＣＨ２ＯＣ２Ｈ５,Ｃ－－－ＣＰｈ,ＣＨ－－－ＣＣｌＰｈ）,利用元素分析、ＩＲ,＾１ＨＮＭＲ和ＴＧ－ＤＡＴ对其组成的结构进行了表征。     

三(2-甲基-2-苯基丙基)锡羧酸酯的合成、结构表征和生物活性

苯丁锡（Ｔｏｒｇｕｅ［ＰｈＭｅ２ＣＣＨ２）３Ｓｎ］２Ｏ）是高效杀螨剂［１］,国内已实现工业化生产．为了寻找更好的有机锡杀螨剂新品种,人们曾对托尔克进行衍生化,合成了某些三（２－甲基－２－苯基丙基）锡芳氧乙酸酯［２］和某些长链羧酸及取代苯甲酸酯的衍生物［３］．本文拟合成系列新的三（２－甲基－２－苯基丙基）锡羧酸酯,并对目标化合物进行了结构表征和生物活性测定,反应式如下：（ＰｈＭｅ２ＣＣＨ２）３ＳｎＣｌ（１）ＮａＯＨ（２）ＲＣＯＯＨ（ＰｈＭｅ２ＣＣＨ２）３ＳｎＯ２ＣＲＲ＝ＣＨ３（１）,Ｃ２Ｈ５（２）…     

环状配合物Me_2Si［η~5－C_5H_4Fe（CO）_2］_2SnR_2的合

通过ＳｎＣｌ_２对化合物Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２（Ⅰ）中Ｆｅ－Ｆｅ键的插入反应以及Ⅰ被Ｎａ－Ｈｇ齐还原所生成的相应双铁负离子｛Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）_２］_２｝~（２－）与ＳｎＲ_２Ｃｌ_２（Ｒ＝Ｍｅ，Ｐｈ）的亲核反应，合成了环状化合物Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）_２］_２ＳｎＲ_２［Ｒ＝Ｃｌ（１），Ｍｅ（２），Ｐｈ（３）］。以元素分析、ＩＲ和~１ＨＮＭＲ谱表征了它们的结构，并用Ｘ射线衍射测定了配合物３的晶体结构。３为单斜晶系，空间群Ｐ２_１／ｎ，ａ＝１．０３８４（３）ｎｍ，ｂ＝１．６３８４（１）ｎｍ，ｃ＝１．５７６２（５）ｎｍ，β＝９７．９３（２）°，Ｖ＝２．６５６（２）ｎｍ~３，Ｚ＝４，Ｄｘ＝１．７１ｇ／ｍＬ。     

Theoretical Studies on Substituent Effect of the Reaction of Amide and Formaldehyde

The thermodynamic properties of the reaction of amide and formaldehyde were calculated via B3LYP method when substituents chosen included CH3,CH2CH3,CH2CH2CH3,CH2CH2CH2CH3,CH(CH3)2,CH2CH(CH3)2,CH(CH3)CH2CH3 and C(CH3)3.Based on the optimization of the structures for reactants and products,the thermodynamic functions of all the species for an actual state were obtained.The thermodynamic data and the equilibrium constants were investigated within a temperature range of 300―343.15 K.The calculated results show that the reaction is exothermic and spontaneous.The trends of all thermodynamic properties are consistent with the temperature.The preferential order of the substituent effect is CH2CH(CH3)2CH(CH3)CH2CH3CH2CH2CH2CH3 CH2CH2CH3CH2CH3≈CH(CH3)2C(CH3)3≈CH3.     

Self-assembly and odd-even effects of cis-unsaturated carboxylic acids on highly oriented pyrolytic graphite

The self-assembly of several cis-unsaturated carboxylic acids of the structure cis-CH3(CH2)p-1CH=CH(CH2)m-1COOH on highly oriented pyrolytic graphite (HOPG) was studied. The impact of the interior cis-CH=CH group and the molecular chain length on their self-assembled structures was considered. Due to the cis conformation of the -HC=CH- group in the interior of these molecules, they display self-assembled structures significantly different from saturated acids with all-trans configurations. As an example of the class of molecules cis-CH3(CH2)p-1CH=CH(CH2)2n-1COOH (p not equal 2n) (p=8, n=7), cis-CH3(CH2)7CH=CH(CH2)13COOH self-assembles into two kinds of enantiomer domains with opposite 2-D chirality. Due to the steric restriction of the interior cis-HC=CH group, all chains with acid groups are packed at the same side of a lamella, a head-to-head arrangement which is different from the head-to-tail packing of saturated all-trans acids. However, cis-CH3(CH2)7CH=CH(CH2)8COOH, considered as one example of the group cis-CH3(CH2)p-1CH=CH(CH2)2n-2COOH (p not equal 2n-1) (p=8, n=5), does not form any stable self-assembled domain, consistent with the molecular arrangement model. This difference in self-assembly behavior between cis-CH3(CH2)p-1CH=CH(CH2)2n-1COOH (p not equal 2n) and cis-CH3(CH2)p-1CH=CHC2n-2COOH (p not equal 2n-1) shows an odd-even chain-length effect of cis-CH3(CH2)p-1CH=CH(CH2)m-1COOH (p not equal m, m=2n or 2n-1). For another category of molecules, cis-unsaturated acids with equal numbers of all-trans carbon atoms on both sides of the cis-CH=CH group, cis-CH3(CH2)m-1CH=CH(CH2)m-1COOH (m=2n or 2n-1), display another odd-even effect. cis-CH3(CH2)7CH=CH(CH2)7COOH, one example of cis-CH3(CH2)2n-1-CH=CH(CH2)2n-1COOH (n=4), is predicted to form both an enantiomer and a nonchiral racemic structure, which is in accordance with the experimental observation of its self-assembled monolayer. However, cis-CH3(CH2)2n-2CH=CH(CH2)2n-2COOH does not form a stable self-assembled domain due to the same steric repulsion as that seen in the cis-CH3(CH2)7CH=CH(CH2)8COOH structure. These odd-even effects demonstrate that molecular self-assembly can be significantly tailored by slightly changing the molecular chain length.     

双丙炔醇酯类化合物的合成与表征

合成了5个新的二丙炔醇酯类化合物[(CO2CH2C≡CH)2(1),CH2(CO2CH2C≡CH)2,(2),(CH2CO2CH2C≡CH2)(3),(CHCO2CH2C≡CH)2,(4),C6H4-1,4-(CO2CH2C≡CH)2,(5)]，并对其进行了C／H，IR和^1H NMR等表征。     

Photodissociation of S atom containing amino acid chromophores

Photodissociation of 3-(methylthio)propylamine and cysteamine, the chromophores of S atom containing amino acid methionine and cysteine, respectively, was studied separately in a molecular beam at 193 nm using multimass ion imaging techniques. Four dissociation channels were observed for 3-(methylthio)propylamine, including (1) CH(3)SCH(2)CH(2)CH(2)NH(2)-->CH(3)SCH(2)CH(2)CH(2)NH+H, (2) CH(3)SCH(2)CH(2)CH(2)NH(2)-->CH(3)+SCH(2)CH(2)CH(2)NH(2), (3) CH(3)SCH(2)CH(2)CH(2)NH(2)-->CH(3)S+CH(2)CH(2)CH(2)NH(2), and (4) CH(3)SCH(2)CH(2)CH(2)NH(2)-->CH(3)SCH(2)+CH(2)CH(2)NH(2). Two dissociation channels were observed from cysteamine, including (5) HSCH(2)CH(2)NH(2)-->HS+CH(2)CH(2)NH(2) and (6) HSCH(2)CH(2)NH(2)-->HSCH(2)+CH(2)NH(2). The photofragment translational energy distributions suggest that reaction (1) and parts of the reactions (2), (3), (5) occur on the repulsive excited states. However, reaction (4), (6) occur only after the internal conversion to the electronic ground state. Since the dissociation from an excited state with a repulsive potential energy surface is very fast, it would not be quenched completely even in the condensed phase. Our results indicate that reactions following dissociation may play an important role in the UV photochemistry of S atom containing amino acid chromophores in the condensed phase. A comparison with the potential energy surface from ab initio calculations and branching ratios from RRKM calculations was made.     

1-丙醇和2-丙醇的真空紫外光电离质谱研究

研究了在9.84 – 11.80 eV光子能量范围内1-丙醇和2-丙醇的光电离和离解光电离，测量了1-丙醇离解电离产生的碎片离子CH3CH2CH2OH+, CH3CH2CHOH+, CH2CH2OH+, CH3CH2CH2+, CH3CH=CH2+和CH2OH+及2-丙醇离解电离产生的碎片离子CH3CH(OH)CH3+, CH3C(OH)CH3+, CH3CHOH+, CH2=CHOH+, CH3CHCH3+和CH3CH=CH2+的光电离效率谱，得到了这些离子的出现势。结合从头算理论计算，给出了1-丙醇的碎片离子CH3CH2CHOH+, CH2CH2OH+, CH3CH2CH2+, CH3CH=CH2+, CH2OH+和2-丙醇的碎片离子CH3C(OH)CH3+, CH3CHOH+, CH2=CHOH+, CH3CHCH3+, CH3CH=CH2+等的解离通道和解离能。理论计算结果与实验结果符合得很好。     

Au nanoparticles stabilised by PEGylated low generation PAMAM dendrimers: design, characterisation and properties

The preparation and characterisation of a series of well-defined low generation (poly)amidoamine (PAMAM)-based dendrimers with end-grafted ethylene glycol ether moieties of type N(CH(2)CH(2)C(O)NHCH(2)CH(2)NR(2))(3) (3a, R=CH(2)CH(2)C(O)OCH(2)CH(2)OCH(3); 3b, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5); 3c, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(9)CH(3)), [CH(2)N(CH(2)CH(2)C(O)NHCH(2)CH(2)NR(2))(2)](2) (4, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5)) and (R(2)NCH(2)CH(2)NHC(O)CH(2)CH(2))N[CH(2)CH(2)N(CH(2)CH(2)C(O)NHCH(2)CH(2)NR(2))(2)](2) (5a, R=CH(2)CH(2)C(O)OCH(2)CH(2)OCH(3); 5b, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5); 5c, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(9)CH(3)) and their application for the stabilisation of gold nanoparticles (Au NPs) is described. These dendrimers were prepared by a consecutive divergent synthesis methodology including Michael addition and amidation cycles. For comparison, amidoamine related model compounds N(C(3)H(7))R(2) (1, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5)) and [CH(2)NR(2)](2) (2, R=CH(2)CH(2)C(O)O(CH(2)CH(2)O)(2)C(2)H(5)) were also synthesised to estimate the minimum required donating capabilities of the stabiliser. Loading the appropriate dendritic templates with H[AuCl(4)] (12) and subsequent reduction of the respective metallodendrimers with Na[BH(4)] produced dendrimer encapsulated gold colloids. The dendrimeric scaffold, the length of the ethylene glycols, the adjusted stabilizer:gold ratio and the duration of reaction time affects the average Au particle diameter in a range of 4.0 (±0.9) to 58.5 (±14.5) nm. Furthermore, depending on the nature of the stabiliser, nanoparticles were formed having spherical or multiple morphologies. Characterisation by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV/vis, and IR spectroscopy revealed that Au NPs are formed and protected inside the dendrimer scaffold.     

二氟二碘甲烷与乙烯基乙醚的反应及其产物的化学转化

二氟二碘甲烷(CF2I2,1)与乙烯基乙醚和Na2S2O4在DMSO和乙醇的混合溶剂中反应得3,3-二氟-3-碘丙醛的乙缩醛[ICF2CH2CH(OEt)2](3).3在锌粉的作用下发生偶联反应生成二缩醛[(EtO)2CHCH2CF2CF2CH2CH(OEt)2](5)。缩醛3或5与烯醇硅醚在SnCl4作用下发生交叉偶联反应。3在锌粉或保险粉的引下与烯醇硅醚发生加成反应。3和5分别转化成硫缩醛ICF2CH2CH(SR)2(13),(RS)2CHCH2CF2CF2CH2CH(SR)2(14)或O,S-缩醛。13消HI得1,1-二氟乙烯衍生物。     

Reduction of bis

The reduction of symmetric, fully-substituted titanocene dichlorides bearing two pendant omega-alkenyl groups, [TiCl2(eta5-C5Me4R)2], R = CH(Me)CH= CH2 (1a). (CH2)2CH=CH2 (1b) and (CH2)3CH=CH2 (1c), by magnesium in tetrahydrofuran affords bis(cyclopentadienyl)titanacyclopentanes [Ti(IV)[eta1:eta1: eta5:eta5-C5Me4CH(Me)CH(Ti)CH2CH(CH2(Ti))CH(Me)C5Me4]] (2a), [Ti(IV)[eta1:eta1:eta5: eta5-C5Me4(CH2)2CH(Ti)(CH2)2CH(Ti)(CH2)2C5Me4]] (2b) and [Ti(IV)[eta1:eta1:eta5:eta5-C5Me4(CH2)2CH(Ti)CH(Me)CH(Me)CH(Ti)(CH2)2C5Me4]](2c), respectively, as the products of oxidative coupling of the double bonds across a titanocene intermediate. For the case of complex 1c, a product of a double bond isomerisation is obtained owing to a preferred formation of five-membered titanacycles. The reaction of the titanacyclopentanes with PbCl2 recovers starting materials 1a from 2a and 1b from 2b, but complex 2c affords, under the same conditions, an isomer of 1c with a shifted carbon - carbon double bond, [TiCl[eta5-C5Me4(CH2CH2CH=CHMe)]2] (1c'). The titanacycles 2a-c can be opened by HCl to give ansa-titanocene dichlorides ansa-[[eta5:eta5-C5Me4CH(Me)CH2CH2CH(Me)CH(Me)C5Me4]TiCl2] (3a), ansa-[[eta5:eta5-C5Me4(CH2)8C5Me4]TiCl2] (3b), along with a minor product ansa-[[eta5:eta5-C5Me4CH2CH=CH(CH2)5C5Me4]TiCl2] (3b'), and ansa-[[eta5:eta5-CsMe4(CH2)3CH(Me)CH(Me)CH=CHCH2C5Me4]TiCl2] (3c), respectively, with the bridging aliphatic chain consisting of five (3a) and eight (3b, 3b' and 3c) carbon atoms. The course of the acidolysis changes with the nature of the pendant group; while the cyclopentadienyl ring-linking carbon chains in 3a and 3b are fully saturated, compounds 3c and 3b' contain one asymetrically placed carbon-carbon double bond, which evidently arises from the beta-hydrogen elimination that follows the HCl addition.     

Reaction pathways and free energy barriers for alkaline hydrolysis of insecticide 2-trimethylammonioethyl methylphosphonofluoridate and related organophosphorus compounds: electrostatic and steric effects

Reaction pathways and free energy barriers for alkaline hydrolysis of the highly neurotoxic insecticide 2-trimethylammonioethyl methylphosphonofluoridate and related organophosphorus compounds were studied by performing first-principles electronic structure calculations on representative methylphosphonofluoridates, (RO)CH3P(O)F, in which R = CH2CH2N+(CH3)3, CH3, CH2CH2C(CH3)3, CH2CH2CH(CH3)2, CH(CH3)CH2N+(CH3)3, and CH(CH3)CH2N(CH3)2. The dominant reaction pathway was found to be associated with a transition state in which the attacking nucleophile OH- and the leaving group F- are positioned on opposite sides of the plane formed by the three remaining atoms attached to the phosphorus in order to minimize the electrostatic repulsion between these two groups. The free energy barriers calculated for the rate-determining step of the dominant pathway are 12.5 kcal/mol when R = CH2CH2N+(CH3)3, 15.5 kcal/mol when R = CH3, 17.9 kcal/mol when R = CH2CH2C(CH3)3, 16.5 kcal/mol when R = CH2CH2CH(CH3)2, 13.4 kcal/mol when R = CH(CH3)CH2N+(CH3)3, and 18.7 kcal/mol when R = CH(CH(3))CH(2)N(CH(3))(2). The calculated free energy barriers are in good agreement with available experimentally derived activation free energies, i.e. 14.7 kcal/mol when R = CH(3), 13.4 kcal/mol when R = CH2CH2N+(CH3)3, and 13.9 kcal/mol when R = CH(CH3)CH2N+(CH3)3. A detailed analysis of the calculated energetic results and available experimental data suggests that the net charge of the molecule (M) being hydrolyzed is a prominent factor affecting the free energy barrier (DeltaG) for the alkaline hydrolysis of phosphodiesters, phosphonofluoridates, and related organophosphorus compounds. The electrostatic interactions between the attacking nucleophile OH- and the molecule M being hydrolyzed favor such an order of the free energy barrier: DeltaG(M(+)+OH-) < DeltaG(M0+OH-) < DeltaG(M(-)+OH-), where M+, M0, and M- represent the cationic, neutral, and anionic molecules, respectively. The change of the substituent R in (RO)CH(3)P(O)F from CH3 to CH2CH2N+(CH3)3 is associated with both the electrostatic and steric effects on the free energy barrier, but the electrostatic effect dominates the substituent shift of the free energy barrier. This helps to better understand why the alkaline hydrolysis of (RO)CH3P(O)F with R = CH2CH2N+(CH3)3 and CH(CH3)CH2N+(CH3)3 is significantly faster than that with R = CH3. The effect of electrostatic interaction also helps to understand why the rate constants for the alkaline hydrolysis of phosphodiesters, such as intramolecular second messenger adenosine 3',5'-phosphate (cAMP), are generally smaller than those for the alkaline hydrolysis of the phosphonofluoridates and related phosphotriesters.